   (testing "Using completable future as response."
     (letfn [(handler [ctx]
               (p/promise (fn [resolve reject]
-                           (async/<!! (async/timeout 1000))
+                           (a/<!! (a/timeout 1000))
                            (resolve (http/ok "hello world")))))]
       (with-server {:handler handler}
         (let [response (client/get base-url)]

  (testing "Using manifold deferred as response."
    (letfn [(handler [ctx]
              (let [d (md/deferred)]
                (async/thread
                  (md/success! d (http/accepted "hello world")))
                d))]
      (with-server {:handler handler}

  (testing "Using manifold stream as body."
    (letfn [(handler [ctx]
              (let [d (ms/stream 3)]
                (a/thread
                  @(ms/put! d "hello")
                  @(ms/put! d " ")
                  @(ms/put! d "world")
